为研究直流纵向磁场作用下金属蒸气对熔化极气体保护焊(gas metal arc welding,GMAW)电弧特性的影响,将钨铜复合材料制成特殊钨极代替熔化极产生铜蒸气,利用高速摄像法、光谱测温法以及小孔探测法对其进行了测试研究.结果表明,铜蒸气进...为研究直流纵向磁场作用下金属蒸气对熔化极气体保护焊(gas metal arc welding,GMAW)电弧特性的影响,将钨铜复合材料制成特殊钨极代替熔化极产生铜蒸气,利用高速摄像法、光谱测温法以及小孔探测法对其进行了测试研究.结果表明,铜蒸气进入电弧等离子体后,电弧出现分层,随铜蒸气含量的增加,弧芯外围区域半径随之增加,弧芯区的尺寸减小.当铜含量为0%时,外加直流磁场后,电弧在阴极区收缩阳极区扩张,其轴向最高温度明显上升;电弧压力峰值偏离轴线,在外加磁场强度为0.015 T时呈现双峰分布,电流密度与电弧压力分布趋势相似;随着铜蒸气的介入,弧芯区电弧表现为阴极区收缩,阳极区扩张,弧芯周围的铜蒸气则明显收缩,电弧轴向最高温度上升的幅度明显降低.随着铜含量的增加,电弧的导电面积增加,环向电磁力作用减弱,电弧中心压力下降幅度显著降低,阳极电流密度的分布趋势逐渐趋于扁平化.展开更多
In order to understand the effects of different content of copper vapor entering the arc plasma on the arc behavior,the tungstencopper materials with copper contents of 0%,10%,20%and 30%were made into special tungsten...In order to understand the effects of different content of copper vapor entering the arc plasma on the arc behavior,the tungstencopper materials with copper contents of 0%,10%,20%and 30%were made into special tungsten electrodes,which replaced the melting electrode to generate copper vapor.The effects of different content of copper vapor on the arc morphology,arc voltage,arc pressure,current density and arc axial temperature were studied.When copper vapor was transported into the arc plasma,the arc consisted of two parts:a high brightness arc core and the surrounding green luminous area.Through the observation and measurement of the stabilized arc,the results showed that as the content of copper vapor increased,the radius of the greenish region gradually increased,the brightness and size of the core area gradually decreased,the axial temperature of the arc gradually decreased and arc voltage gradually increased with a maximum difference of 1.5 V.This is because the increase of copper vapor concentration changes the net emission coefficient,resulting in a decrease in arc temperature and electrical conductivity.The distribution of arc pressure and current density showed unimodal distribution on the anode surface,and as the content of copper vapor increased,the distribution curves were gradually flattening.A factor contributing to this is that with the increase of copper vapor concentration,the current tends to flow through the edge of the electrode,which expands the conductive path and makes the arc disperse.And the coupling mathematical model of tungsten electrode and arc were established to further explain the experimental results.展开更多
文摘为研究直流纵向磁场作用下金属蒸气对熔化极气体保护焊(gas metal arc welding,GMAW)电弧特性的影响,将钨铜复合材料制成特殊钨极代替熔化极产生铜蒸气,利用高速摄像法、光谱测温法以及小孔探测法对其进行了测试研究.结果表明,铜蒸气进入电弧等离子体后,电弧出现分层,随铜蒸气含量的增加,弧芯外围区域半径随之增加,弧芯区的尺寸减小.当铜含量为0%时,外加直流磁场后,电弧在阴极区收缩阳极区扩张,其轴向最高温度明显上升;电弧压力峰值偏离轴线,在外加磁场强度为0.015 T时呈现双峰分布,电流密度与电弧压力分布趋势相似;随着铜蒸气的介入,弧芯区电弧表现为阴极区收缩,阳极区扩张,弧芯周围的铜蒸气则明显收缩,电弧轴向最高温度上升的幅度明显降低.随着铜含量的增加,电弧的导电面积增加,环向电磁力作用减弱,电弧中心压力下降幅度显著降低,阳极电流密度的分布趋势逐渐趋于扁平化.
基金Project was supported by the National Natural Science Foundation of China(Grant No.51775256).
文摘In order to understand the effects of different content of copper vapor entering the arc plasma on the arc behavior,the tungstencopper materials with copper contents of 0%,10%,20%and 30%were made into special tungsten electrodes,which replaced the melting electrode to generate copper vapor.The effects of different content of copper vapor on the arc morphology,arc voltage,arc pressure,current density and arc axial temperature were studied.When copper vapor was transported into the arc plasma,the arc consisted of two parts:a high brightness arc core and the surrounding green luminous area.Through the observation and measurement of the stabilized arc,the results showed that as the content of copper vapor increased,the radius of the greenish region gradually increased,the brightness and size of the core area gradually decreased,the axial temperature of the arc gradually decreased and arc voltage gradually increased with a maximum difference of 1.5 V.This is because the increase of copper vapor concentration changes the net emission coefficient,resulting in a decrease in arc temperature and electrical conductivity.The distribution of arc pressure and current density showed unimodal distribution on the anode surface,and as the content of copper vapor increased,the distribution curves were gradually flattening.A factor contributing to this is that with the increase of copper vapor concentration,the current tends to flow through the edge of the electrode,which expands the conductive path and makes the arc disperse.And the coupling mathematical model of tungsten electrode and arc were established to further explain the experimental results.
